A method so far widely known for providing a thermoplastic resin such as a polycarbonate resin or a polystyrene resin with antistatic properties without impairing the transparency thereof comprises applying or incorporating a surfactant to the resin surface or into the resin. However, it is difficult, by such method, to provide permanent antistatic properties, since the surfactant is readily removed upon washing with water or by friction.
Therefore, the following methods for providing permanent antistatic properties while maintaining the transparency have been proposed: (1) the method comprising adding to a polycarbonate resin a polyether ester, an ionic surfactant, a phenolic antioxidant and a spiro type phosphite compound (cf. e.g. Japanese Kokai Publication Hei-11-343401), (2) the method comprising adding to a polycarbonate resin a polyether ester derived from a sulfonic acid salt group-containing aromatic dicarboxylic acid and a halogen atom-containing diol (cf. e.g. Japanese Kokai Publication Hei-09-25335), (3) the method comprising adding to a polycarbonate resin a sulfonic acid salt group- and condensed polycyclic hydrocarbon skeleton-containing polyether ester and an ionic antistatic agent (cf. e.g. Japanese Kokai Publication Hei-10-338740), and (4) the method comprising adding to a polycarbonate resin a polyether ester amide derived from a polyamide oligomer and an ethylene oxide adduct of a bisphenol (cf. e.g. Japanese Kokai Publication Hei-07-10989), and the like.